Richard Waller wrote Letter L-502 of 3 March 1714 to discuss recent observations about muscles

March 3, 1714

Never published. The date is New Style, which was eleven days ahead of the Old Style date of 20 February 1714 used by Waller in London.

With this letter, Waller resumes writing to Leeuwenhoek 20 years after his previous letter. He discussed Leeuwenhoek’s recent letter about muscles and adds his own thoughts about muscles in insects.

A copy is found in London, Letter Book Original 15.28, p. 36. The copy, presumably of the letter as it was sent to L., differs at many points with the original manuscript, as noted in the footnotes below. At the end of the manuscript is the note, in Waller’s hand, “Draught of a letter for Mr Leuwenhoek read Feb. the 25th & ordered to be sent to him.”

In Shuckard, Catalogues of the miscellaneous manuscripts (1840), this letter, item 3821 on p. 162, is erroneously dated 24 February.

Waller and Leeuwenhoek exchanged 11 letters in the early 1690s while Waller was editor of Philosophical Transactions, volumes 17 and 18. Waller initiated the exchange with Letter L-215 of 12 February 1692 (2 February 1692 O.S.) in which he comments on Leeuwenhoek’s observations in recent letters. See the improved translation of Letter L-215 in this volume.

Waller followed that with three other letters. Letter L-224 of 8 May 1693 (28 April 1693 O.S.), discussed the microscopical structure of the feather and Waller’s view of univocal generation. In Letter L-234 of 10 February 1694 (31 January 1693/4 O.S.), Waller requested that Leeuwenhoek investigate the colours of birds’ feathers and the presence of sperm in the egg. Finally, the lost Letter L-243 of 2 May 1694 (22 April 1694 O.S.), is known only by reference in Letter 138 L-244 of 26 May 1694 to Waller.

Leeuwenhoek responded to Waller with seven letters. The first, Letter L-217 of 22 April 1692, discussed among other things, seeds of spices in urine and the construction of an air pump and experiments with different liquids. Leeuwenhoek published it in Derde Vervolg der Brieven (Third continuation of the letters, 1693) and Arcana naturae detecta (Secrets of nature detected, 1695). The last, Letter L-245 of 14 September 1694, was about printed copies of his portrait that he sent to the Royal Society as well as a discussion of different opinions about the circulation of blood in animals. Leeuwenhoek published it in Vijfde Vervolg der Brieven (Fifth continuation of the letters, 1693) and Arcana naturae detecta. Neither was published in Philosophical Transactions. Leeuwenhoek did not publish the five letters between these two. All of them are cover letters that discuss the sending and receiving of Leeuwenhoek’s letters and copies of Philosophical Transactions.

The present letter from Waller, twenty years later, begins a series of four letters from Waller to Leeuwenhoek over the following six months, ending with Letter L-508 of 30 August 1714, several months before Waller’s death. Waller probably also wrote a fifth letter, Letter L-503 of 8 March 1714, on behalf of the Royal Society. His letters dealt with the business of Philosophical Transactions and Royal Society meetings. He also repeatedly encouraged Leeuwenhoek’s study of muscles and asked him to focus especially on insects’ muscles.

Leeuwenhoek did not reply directly to Waller, but he wrote four letters to the Royal Society in those months, all about muscle fibers in a variety of mammals, birds, rodents, and insects: Letter L-504 of 22 June 1714, Letter L-507 of 21 August 1714, Letter L-509 of 26 October 1714, and Letter L-512 of 9 November 1714. After that, L. did not write another letter to the Royal Society until mid-1717. These letters are all in L.’s Send-Brieven. None of them was published in Philosophical Transactions because Edmond Halley was its editor.


The manuscript is to be found in London, Royal Society, Early Letters W3.80, 1 page. Copied and pasted from Collected Letters, vol. 20, "this volume" in the footnotes.

A letter to Mr Anthony van Leuwenhoeck.

20 February 1713/4


            It is now near 20 years since I had the happiness either to write or receive[1] a letter from you[2]. But the Royal Society having received yours of the ____[3], I was ordered[4] to return you an answer with their thanks for your communications which opportunity of showing my respect I readily embraced being very desirous of renewing my correspondence with a person so valuable for the many happy discoveries you have made in natural subjects by your excellent microscopes, and[5] so much respected by the Society as yourself[6].

            Muscular motion is a subject which has exercized the minds[7] and pens of several learned and inquisitive naturalists, such as Steno, Dr. Croone, Borelli[8], and many others as you well know[9] by whom many observations were[10] made in order to explain the mechanism of so curious an engine[11] to which inquiry you have contributed early[12]; by your microscopical discoveries, you have gratified the world with[13] the texture of the minute parts and compounding fibres of a muscle both in flesh and fish of several kinds; nor is the subject[14] so far exhausted but[15] there still remains enough to satisfy the curiosity of the inquirer.

            Your last letter concerning the minute fibrillae of the muscles in a whale compared with those of smaller animals[16] is curious, seeming to show[17] that the greater strength of the muscles in those large animals does not proceed from the minute or least fibrilla being larger than they are in the[18] lesser animals but from there being a greater congeries[19] or number of them bound[20] together by[21] the external membrane[22] encompassing the whole body of the muscle[23] as a large rope[24] has its greater strength from the numerousness of the fibres of the hemp that[25] compose it, though each particular fibre has the same size and texture[26] as it has in a small thread[27].

            How far this may answer in animals comparatively large[28] such as[29] oxen, sheep, and possibly mice I doubt not nor in the least question your observations but[30] offer it as my own that[31] it must be otherwise in respect to insects[32] whose minute limbs seem to require a more fine and delicate texture of their little muscles, which muscles are themselves not visible[33] to the naked eye and therefore[34] seem to require a proportional finesse or delicacy in their component fibres[35], the same may be thought[36] of their tendons, arteries, and veins, and likewise of the fluids of what kind soever[37] passing through them. How far your diligence and microscopes can[38] be able to carry on and trace this discovery, this learned[39] Society would with satisfaction be informed of if your leisure and other occasions permit.

            Sir, whatever other discoveries your own inclination, genius, or opportunity may lead you to undertake[40] will be always gratefully received by us: The Transactions herewith sent you from the Royal Society[41] will inform you of some of the matters that have been laid before them[42]; and I shall endeavour in my future answers to any of yours which we cannot receive too often to give you some information of whatever is new in natural philosophy, occurs to sir, yours etc.


[1] to write or receive, in ms., of writing or receiving.

[2] L.’s previous and final letter to Waller is Letter 139 [84] L-245 of 14 September 1694, Collected Letters, vol. 10. L. did not address another letter to the Royal Society or any of its officers until Letter 169 [102] L-295 of 10 July 1696, idem, vol. 11.

[3] The date is missing in both the manuscript and the copy. L.’s previous letter to the Royal Society is Letter 302 [VII] L-496 of 28 June 1713, Collected Letters, vol. 17. Read at a meeting of the Royal Society on 22 October 1713 O.S., the letter discusses little animals on duckweed plants and in dental plaque from L.’s mouth. The letter Waller refers to here is Letter 304 L-499 of 12 October 1713 to Hans Sloane, which is a cover letter for a copy of L.’s Letter 296 [I] L-489 of 8 Novmber 1612 to Anthonie Heinsius that Sloane had asked L. to send to him. That letter was read on 4 February 1714 O.S. and extracted in Philosophical Transactions, vol. 29, no. 339. See Letter L-500 to Sloane of 24 October 1713, note 9, in this volume.

[4] I was ordered, in ms., ordered me.

[5] Ms. adds, upon that account.

[6] by the Society as yourself, in ms., by the Royal Society.

[7] exercized the minds, in ms., employed the thoughts.

[8] Nicolas Steno (1638-1686), New Structure of the Muscles and Heart and Specimen of Elements of Myology. See the Biog. Reg., Collected Letters, vol. 4, p. 349. William Croone (1633-1684), On the reason of the movement of the muscles. See the Biog. Reg., idem, vol. 3, p. 477. Giovanni Alfonso Borelli (1608-1679), On the Movement of Animals. The original publications were all in Latin, so it is unlikely that L. read them; however, he may well have been familiar with them through discussions with friends who could read Latin.

[9] such as Steno, Dr. Croone, Borelli, and many others as you well know, in ms., I need not mention Dr Croon, Steno, Borelli and others sufficiently known.

[10] were, in ms., and experiments have been.

[11] Ms. adds, as a muscle is.

[12] contributed early, in ms., not a little contributed.

[13] discoveries, you have gratified the world with, in ms., observations of.

[14] nor is the subject, in ms., yet I may say the subject is not.

[15] Ms. adds, that.

[16] Waller refers here to L.’s Letter 297 [II] L-490 of 8 November 1712 to Anthonie Heinsius., Collected Letters, vol. 17.

[17] show, in ms., prove.

[18] the, in ms., comparatively.

[19] Ms. adds, collection.

[20] Ms. adds, up.

[21] by, in ms., in.

[22] Ms. adds, or tegument.

[23] In the ms., the rest of the paragraph is crossed out.

[24] rope, in ms., cable.

[25] that, in ms., which.

[26] and texture, in ms., texture of its parts and strength.

[27] Ms. adds, of hemp.

[28] Ms. adds, in respect of insects.

[29] Ms. adds, whales.

[30] observations but, in ms., observations; but I presume to.

[31] that, in ms., thoughts, that I apprehend.

[32] to insects, in ms., of insects, especially the smaller those living atomes, such as mites & the like.

[33] muscles are themselves not visible, in ms., in themselves are scarce visible at least.

[34] Ms. adds, these.

[35] proportional finesse or delicacy in their component fibres, in ms., more fine and delicate texture of their little muscles.

[36] thought, in ms., judged.

[37] and veins, and likewise of the fluids of what kind soever, in ms., veins, nerves and of the fluids.

[38] can, in ms., may.

[39] and trace this discovery, this learned, in ms., this inquiry, the Royal.

[40] undertake, in ms., to attempt and make.

[41] from the Royal Society, in ms., by the Society’s order. Waller probably refers to the same volume 27 of Philosophical Transactions that Sloane discusses in Letter L-500 of 24 October 1713, in this volume. See note 8.

[42] them, in ms., us.